Attachment 1-1 Guidance for Developing Ecological Soil Screening Levels (Eco-SSLs) Review of Existing Soil Screening Benchmarks OSWER Directive 92857-55 November 2003 This page intentionally left blank A CRITICAL REVIEW OF METHODS for DEVELOPING ECOLOGICAL SOIL QUALITY GUIDELINES AND CRITERIA Prepared for American Petroleum Institute Biomonitoring Task Force 1220 L Street, Northwest Washington, DC 20005-4070 Prepared by ecological planning and toxicology, inc. 5010 S.W. Hout Street Corvallis, OR 97333-9540 October 1999 critical review of soil criteria methods EXECUTIVE SUMMARY In support of the U.S. Environmental Protection Agency (USEPA) development of soil criteria referred to as Ecological Soil Screening Level to screen contaminated sites, methods used elsewhere to develop similar criteria were reviewed. Technical guidance documents from Europe (most notably, The Netherlands), Australia, Canada (Federal), British Columbia, and Oak Ridge National Laboratory were examined. None of the U.S. states have distinct methods. Technical staff in each of the countries were also consulted. In addition, USEPA methods for development of water and sediment criteria were reviewed. Three generic methods have been used to set protective soil concentrations throughout the world. · Type 1 selects the lowest reported toxicity value and divides by an assessment (safety) factor. · Type 2 arrays all reported values in a statistical distribution and selects a particular percentile. · Type 3 ranks all reported soil concentrations from lowest to highest and chooses the upper boundary such that no toxic effects are known to occur at lower concentrations; however, higher concentrations do not always cause toxicity. The final goal of all environmental protection values, regardless of media, is protection while being reasonable. How issues such as level of protection, use of assessment factors, background levels, and minimum data requirements are addressed varies with jurisdictions, which in turn affects the final values. Compilation of soil protection values revealed substantial differences among the various jurisdictions. Generally, the different values were drawn from the same world-wide body scientific studies. Therefore the differences among these jurisdictions primarily reflect differences in policy, rather than technical rigor or quality of the underlying science. i critical review of soil criteria methods TABLE OF CONTENTS 1. INTRODUCTION.................................................................................................................. 1-1 1.1. INFORMATION SOURCES ........................................................................................ 1-2 2. APPROACHES FOR ECO-SSL DEVELOPMENT .............................................................. 2-1 2.1. EUROPEAN................................................................................................................. 2-2 2.1.1. Distribution Based Method....................................................................... 2-4 2.1.2. Factor Application Method ....................................................................... 2-5 2.1.3. Equilibrium Partitioning Method ............................................................... 2-6 2.1.4. Wildlife...................................................................................................... 2-6 2.2. CANADIAN .................................................................................................................. 2-7 2.2.1. Canadian Council of Ministers of the Environment ................................. 2-7 2.2.2. British Columbia..................................................................................... 2-10 2.2.3. Ontario.................................................................................................... 2-12 2.2.4. Other provinces...................................................................................... 2-13 2.3. AUSTRALIA............................................................................................................... 2-13 2.4. OAK RIDGE NATIONAL LABORATORY (ORNL).................................................... 2-15 2.4.1. Microorganisms, Invertebrates and Plants ............................................ 2-15 2.4.2. Wildlife.................................................................................................... 2-16 2.5. SAVANNAH RIVER SITE.......................................................................................... 2-17 2.6. U.S. FISH AND WILDLIFE SERVICE....................................................................... 2-17 2.7. STATES AND PROVINCES...................................................................................... 2-18 2.8. USEPA....................................................................................................................... 2-18 2.9. USEPA WATER QUALITY CRITERIA...................................................................... 2-19 2.10. SEDIMENT QUALITY CRITERIA.............................................................................. 2-20 2.10.1. Equilibrium Partitioning Method ............................................................. 2-20 2.10.2. Effects Range Method............................................................................ 2-20 3. SOIL CRITERIA VALUES .................................................................................................... 3-1 4. CRITICAL REVIEW .............................................................................................................. 4-1 4.1. APPLICATION............................................................................................................. 4-1 4.2. MINIMUM DATA SET REQUIREMENTS ................................................................... 4-3 4.3. TOXICITY ENDPOINT ................................................................................................ 4-3 4.4. EXTRAPOLATIONS .................................................................................................... 4-5 ii critical review of soil criteria methods 4.5. BIOAVAILABILITY ADJUSTMENTS........................................................................... 4-6 4.6. ASSESSMENT FACTORS ......................................................................................... 4-6 4.7. EQUILIBRIUM PARTITIONING .................................................................................. 4-8 4.8. VALIDATION................................................................................................................ 4-9 4.9. PEER REVIEW.......................................................................................................... 4-11 5. CONCLUSIONS ................................................................................................................... 5-1 REFERENCES ................................................................................................................................1 Appendix A. Summary tables of methods for derivation of ecologically protective soil values ...................................................................................................................... A-1 Appendix B. Guiding principles used by the Canadian Council of Ministers of the Environment for deriving soil protection values......................................................B-1 Appendix C. Comparison of methods for deriving ecologically protective soil values................C-1 Appendix D. Published soil values for use in screening, cleanup, or monitoring contaminated sites..................................................................................................D-1 iii critical review of soil criteria methods LIST OF FIGURES Figure 2-1 Frequency distribution of toxicity threshold (hypothetical). .................................... 2-5 Figure 2-2. Example calculation of effects distribution for derivation of critical soil values by British Columbia.................................................................................... 2-12 Figure 2-3. Sediment quality criteria derivation by Effects Range determination (Long and Morgan, 1991)................................................................................................ 2-21 Figure 4-1. Derivation of the Benchmark Dose for human health risk assessment................. 4-4 LIST OF TABLES Table 1-1. Documents and other information sources reviewed .................................................. 1-3 Table 2-1. Contaminated sites soil criteria in Europe.................................................................... 2-3 Table 2–2. Assessment factors for determination of soil quality criteria (Europe) ....................... 2-6 Table 2-3. Uncertainty factors for determination of soil quality criteria using the weight of evidence approach (Canada) ................................................................................. 2-8 Table 2-4. Uncertainty factors for determination of soil quality criteria using the LOAEC method (Canada) .................................................................................................... 2-9 Table 2-5. Assessment factors for determination of soil quality criteria (Australia).................... 2-15 Table 3-1. Critical limits for heavy metals in soils in several countries1........................................ 3-1 iv critical review of soil criteria methods ABBREVIATIONS ACR Acute to Chronic Ratio BCF Bioconcentration Factor BCME British Columbia Ministry of Environment, Lands, and Parks BW Body Weight CCME Canadian